“The nature of faith cannot be rightly perceived unless these two things are known: (1) of what acts it consists; (2) what is its object…
The fifth is the act of reception of Christ or of adhesion and union, by which we not only seek Christ through a desire of the soul and fly to Him, but apprehend and receive Him offered, embrace Him found, apply Him to ourselves and adhere to and unite ourselves to Him.
For as God freely offers His own Son in the gospel to the sinful soul, burdened and cast down and broken by a sense of his sins, and Christ offers Himself with all His benefits and the fulness of salvation residing in Him, so the soul (firmly persuaded of the fulness of salvation in Christ, seriously flying to Him and earnestly desiring communion with Him) cannot help embracing with the highest freedom of the will that supreme good offered, and the inestimable treasure, selling all for Him (Mt. 13:44), resting upon Christ as the sole Redeemer and delivering and making himself over, and so firmly retaining Him that he is prepared to lose anything else rather than reject Him.
This is the formal and principal act of justifying faith, usually termed “reception”:
“As many as received Him” (i.e., “who believed on His name,” Jn. 1:12); believers are said “to receive the gift of righteousness” (Rom. 5:17); “to receive Christ” (Col. 2:6); “I found him whom my soul loveth: I held him, and would not let him go” (Cant. 3:4); sometimes “meat and drink” (Mt. 5:6; Jn 6:51); the “putting on of Christ” (Gal. 3:27).
And because the soul thus apprehending Christ reclines upon Him and rests upon and cleaves to Him, faith is also sometimes described as an act of “reclining” (Ps. 71:5; Isa. 10:20; 48:2; 50:10; Mic. 3:11); as also an act of adhesion and binding closely, and of the most strict union by which we are bone of His bone and flesh of His flesh and one with him; and Christ Himself dwells in us (Eph. 3:17) and we in Him (Jn. 15:5).
From this union of persons arises the participation in the blessings of Christ, to which (by union with Him) we acquire a right (to wit, justification, adoption, sanctification and glorification).”
–Francis Turretin, Institutes of Elenctic Theology, ed. James T. Dennison Jr., trans. George Musgrave Giger, vol. 2 (Phillipsburg, NJ: P&R Publishing, 1992–1997), 2: 560, 563.